1. Field of the Invention
The present invention relates to information delivery apparatuses and methods that deliver information to users by using communication lines, and in particular, to an apparatus and method in which, when information is delivered to a user by a network such as the Internet, a delay occurring until the delivered information reaches the user is reduced.
2. Description of the Related Art
In recent years, various types of information have become available by using networks such as the Internet. The use of the Internet enables inexpensive communication compared with communication using subscriber lines. Accordingly, the Internet is used to deliver, to users, direct e-mail messages which have been conventionally sent by postal mail.
In information deliver using the Internet, delivered information is not limited to only text information, but large-amount information, such as images, is transmitted in large volume. Thus, on the Internet, which is constituted by connecting various networks, there is a high possibility that a delay in information delivery may occur.
An avoiding method for avoiding the delay in information delivery (e.g., Japanese Unexamined Patent Application Publication No. 2001-202318, the “Description of the Related Art” section, and page 3) is known in which information transmitting servers are distributed and a transmission path between each server and each user is shortened, or a particular server is prevented from having a concentrated load to avoid a delay information delivery.
Also, an invention which sends advertisement information to user with appropriate timing, such as delivery of guidance of a lunch menu to users before a lunch hour, has been disclosed (e.g., Japanese Unexamined Patent Application Publication No. 2002-189662, pp. 3 to 4)
Moreover, an information delivery system is known in which a menu of information whose deliver is desired by each user and desired timing (such as each time of updating content, a fixed time of everyday, or a time on or before a designated time) for the information delivery are selectively registered and the information is delivered with the registered desired timing. This information delivery system also has a disclosure (e.g., Japanese Unexamined Patent Application Publication No. 11-136365, paragraph numbers 0017, 0018, and 0033) indicating that, based on load information predicting a load per hour of a communication network for delivering the information, and the desired timing for delivery, the desired information is delivered in a time zone which satisfies the desired timing and which has the minimum load on the communication network.
With the method disclosed in Japanese Unexamined Patent Application Publication No. 2001-202318, and with extensive advances in technology, such as an increased transmission speed on a transmission path, an increased compression factor of information itself to be transmitted/received, and advances in signal processing technology, a delay in information delivery is reduced. However, it is highly expected that, by using the information delivery systems disclosed in Japanese Unexamined Patent Application Publication Nos. 2002-189662 and 11-136365, an increasing number of users transmit information and amounts of information flowing on the network remarkably increase. Thus, improvements in various types of hardware are essential to avoid a delay in information delivery, but it is expected that it is difficult for only the improvements in the hardware to solve the delay in information delivery.
Accordingly, it is anticipated that also an information delivery method, such as information delivery based on a time that a user desires delivery or timing, as in Japanese Unexamined Patent Application Publication No. 2002-189662 or 11-136365, is a solution to avoidance of a delay in delivery.
As in Japanese Unexamined Patent Application Publication No. 2002-189662, a time designating method is effective when there is enough time from transmission of information to arrival of the information at a user since the information can be delivered on or before a designated time. However, it may not be said that the time designating method is not suitable for information delivery which requires instancy.
Also, in the invention described in Japanese Unexamined Patent Application Publication No. 11-136365, a user designates the priorities of pieces of desired information, and sets desired timing for delivery to “each time of updating content”, whereby, in accordance with the descending order in priority of the pieces of information, a piece of information is delivered to the user each time the piece of information is updated. In this invention, when many users assign high priority to the same piece of information and sets desired timing for delivery to “each time of updating content”, large amounts of information are delivered at a time. In this case, depending on the status of a network, just after updating of content, the updated content cannot reach even users who have set the desired timing for delivery to “each time of updating content”, thus causing a delay in information reception. Also, even if users are divided into free-membership users and paid-membership users and information is distributed to the paid-membership users with higher priority, the more the number of the paid-membership users is, the higher the load on the network will be, thus causing delays in information delivery.